1. Field of the Invention
The present invention relates to an image recording apparatus including a plurality of line-type printheads.
2. Discussion of Related Art
In an image recording apparatus which records an image on each of a plurality of recording media such as cut sheets, in order to enhance throughput, for example, it can be generally considered that a distance in a medium feed direction between two recording media (a preceding recording medium and a following recording medium) which are sequentially fed one by one in the medium feed direction is made as small as possible. For example, Patent Document 1 (JP-A-2001-277645) discloses an image recording apparatus including a serial-type printhead which moves in a main scanning direction of a plurality of recording media and records an image on each of the recording media, the printhead concurrently recording respective images on each of the two recording media while being opposed to the two recording media. According to Patent Document 1, the recording media are fed such that the following recording medium is fed to a recording area to be opposed to the printhead before the preceding recording medium passes through the recording area. Accordingly, the printhead concurrently records respective images on a trailing end portion of the preceding recording medium and a front end portion of the following recording medium.
In a case where the prior art disclosed in Patent Document 1 is applied to an image recording apparatus including a plurality of line-type printheads which do not move in the main scanning direction of the recording media and record an image on each of the recording media, the recording media are fed by a feeding device such that the following recording medium is fed to a recording area before the preceding recording medium passes through the recording area, and the line-type printheads concurrently records respective images on the trailing end portion of the preceding recording medium and the front end portion of the following recording medium at the recording area. The recording area corresponds to an area between a most upstream one and a most downstream one of the printheads in the medium feed direction of the recording media by the feeding device.
As mentioned above, when the recording media are fed by the feeding device such that the following recording medium is fed to the recording area before the preceding recording medium passes through the recording area, a plurality of pieces of drive data for the following recording medium should be supplied to the printheads before the preceding recording medium passes through the recording area. On the other hand, times necessary for supplying the pieces of drive data for one recording medium to the line-type printheads differ from each other depending on recording conditions. For example, data amounts of the drive data are different from each other in a case where an image of monochrome is recorded on the recording medium and a case where an image of color is recorded thereon. In a case where the remaining recording conditions are identical with each other in a mode of monochrome-recording and a mode of color-recording, the time necessary for supplying the pieces of drive data for one recording medium to the line-type printheads in the case of color-recording is longer than that in the case of monochrome-recording. Therefore, when the image of color is recorded on the recording medium under the same recording condition as that of the case of monochrome-recording, it is highly possible that the drive data for the following recording medium cannot be supplied to the printheads before the following recording medium, which is fed next to the preceding recording, is fed to the recording area.
In order to prevent the above-mentioned problem, in an image recording apparatus disclosed in Patent Document 1, when an image is to be recorded across two consecutively fed recording media, and at a timing of initiation of the image recording, a portion of data of the image corresponding to the following recording medium is still being received or the portion of the data has been received but is being converted or decoded into raster type data, the image recording apparatus initiates the concurrent image recording across the two recording media only after the converting of the portion of the data is complete. In the image recording apparatus having the line-type printheads, however, a speed of feeding the recording media within the recording area is necessary to be changed, so that it is generally difficult to apply the above-mentioned manner to the image recording apparatus having the line-type printheads.
In order that the images are concurrently recorded on the preceding recording medium and the following recording medium at the recording area in either one of the color-recording mode and the monochrome-recording mode, the recording conditions should be determined such that the drive data for the following recording medium can be supplied in time to the printheads in either one of the color-recording mode and the monochrome recording mode. Under this circumstance, the recording conditions applicable to the image recording apparatus are restricted.